16 research outputs found

    Soporte a la Evolución Dinámica de Tipos Arquitectónicos

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    Los sistemas software con una fuerte naturaleza dinámica suponen un reto para la ingeniería del software. Este tipo de sistemas requieren de mecanismos que les permitan modificar tanto estructura como comportamiento en tiempo de ejecución, para adaptarse a las distintas situaciones que puedan presentarse. El área de arquitecturas software, que permite describir la estructura de los sistemas complejos a un alto nivel de abstracción, proporcionados grados de dinamismo para la construcción de sistemas dinámicos, dependiendo de si lo que evoluciona es la configuración de la arquitectura o los tipos que componen dicha arquitectura. El primer tipo de evolución, denominado reconfiguración dinámica, permite a una arquitectura software cambiar su configuración en tiempo de ejecución, creando/destruyendo instancias de elementos arquitectónicos y/o las conexiones entre ellas. El segundo tipo de evolución, que denominamos evolución dinámica de tipos arquitectónicos, permite cambiar completamente la especificación arquitectónica de un sistema dinámicamente, bien introduciendo nuevos tipos arquitectónicos, modificando tipos e instancias en ejecución, o bien introduciendo nuevas conexiones. Este artículo presenta cómo soportar este último grado de dinamismo desde un punto de vista independiente de plataforma. Para ello, se han identificado los diferentes asuntos de interés implicados en el proceso y se han encapsulado en aspectos

    Parallel Processes in HPX: Designing an Infrastructure for Adaptive Resource Management

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    Advancement in cutting edge technologies have enabled better energy efficiency as well as scaling computational power for the latest High Performance Computing(HPC) systems. However, complexity, due to hybrid architectures as well as emerging classes of applications, have shown poor computational scalability using conventional execution models. Thus alternative means of computation, that addresses the bottlenecks in computation, is warranted. More precisely, dynamic adaptive resource management feature, both from systems as well as application\u27s perspective, is essential for better computational scalability and efficiency. This research presents and expands the notion of Parallel Processes as a placeholder for procedure definitions, targeted at one or more synchronous domains, meta data for computation and resource management as well as infrastructure for dynamic policy deployment. In addition to this, the research presents additional guidelines for a framework for resource management in HPX runtime system. Further, this research also lists design principles for scalability of Active Global Address Space (AGAS), a necessary feature for Parallel Processes. Also, to verify the usefulness of Parallel Processes, a preliminary performance evaluation of different task scheduling policies is carried out using two different applications. The applications used are: Unbalanced Tree Search, a reference dynamic graph application, implemented by this research in HPX and MiniGhost, a reference stencil based application using bulk synchronous parallel model. The results show that different scheduling policies provide better performance for different classes of applications; and for the same application class, in certain instances, one policy fared better than the others, while vice versa in other instances, hence supporting the hypothesis of the need of dynamic adaptive resource management infrastructure, for deploying different policies and task granularities, for scalable distributed computing

    Evolución Dinámica de Arquitecturas Software Orientadas a Aspectos

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    Se persigue dotar a los sistemas software altamente disponibles de la capacidad de alterar tanto su estructura como su comportamiento en tiempo de ejecución, afectando al mínimo número de subsistemas que lo forman. Esto se ha realizado a nivel de arquitecturas software y basándose en la separación de asuntos de intéres.Costa Soria, C. (2007). Evolución Dinámica de Arquitecturas Software Orientadas a Aspectos. http://hdl.handle.net/10251/12907Archivo delegad

    Ethylene oxide sterilisation of medical devices : development of mathematical models for prediction of ethylene oxide diffusion and microbial lethality

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    O óxido de etileno (EO) é um agente de esterilização dominante na indústria dos dispositivos médicos, devido à sua efectividade e compatibilidade com a maioria dos materiais. Considerando o crescimento exponencial do mercado de dispositivos médicos sensíveis, complexos e sofisticados, assim como de conjuntos de procedimento customizados (que combinam uma grande diversidade de produtos e gama de polímeros) utilizados em actos médicos e cirúrgicos específicos, o EO emerge como o método de esterilização de eleição. A optimização deste processo constitui um desafio devido ao facto da competitividade do mercado global exigir custo-efectividade, flexibilidade e redução do tempo de ciclo necessário à colocação dos produtos no mercado, sem prejuízo da segurança e assegurando o cumprimento dos requisitos reguladores. A esterilização por EO é um processo multi-paramétrico complexo, que exige uma fase final de arejamento dos materiais. A eficácia destes processos é influenciada por diversas variáveis (e.g. temperatura, humidade, concentração do agente, material alvo), pelo que a sua optimização exige o conhecimento da influência das condições impostas e das suas relações com os produtos. A modelização matemática do processo de esterilização e arejamento permite a definição das condições óptimas para morte microbiana e desgaseificação, respectivamente. Tal permite a redução dos tempos de ciclo e/ou concentração de EO, assim como a comparação de diferentes processos de esterilização. Deste modo é possível contribuir para o desenvolvimento de processos com eficiência e flexibilidade acrescidas e a libertação paramétrica da esterilização surge assim cientificamente apoiada. Nesta dissertação foi estudada a influência das condições de processo na esterilização de dispositivos médicos por EO. Este é um processo implementado na empresa Bastos Viegas, S.A., desde 2005. Foram estudados os efeitos e interacções da temperatura, concentração de óxido de etileno e humidade relativa na inactivação do Bacillus subtilis, var. niger (ATCC 9372), o microrganismo de referência usado no controlo do processo. As experiências foram realizadas em câmaras de esterilização, com uma carga de campos cirúrgicos. Aplicou-se um planeamento experimental factorial 23 para avaliação dos efeitos das três variáveis (de acordo com limites comuns de condições operacionais) na letalidade da esterilização por EO. A inactivação do B. subtilis apresentou um comportamento sigmoidal e um modelo baseado em Gompertz foi ajustado com sucesso aos dados experimentais. Características importantes das curvas, tais como atraso inicial e taxa de inactivação foram considerados parâmetros do modelo. A temperatura e a concentração de óxido de etileno foram as variáveis que afectaram significativamente esses parâmetros, pelo que experiências adicionais foram realizadas de forma a incluir o efeito dessas variáveis do processo. Foi desenvolvido um modelo matemático para previsão da morte de B. subtilis expresso em função da temperatura e concentração de EO. Uma vez que a letalidade demonstrou estar directamente relacionada com a concentração de agente esterilizante, compreender a efectividade da esterilização por EO suscita obter a permeabilidade dos materiais ao gás, assim como o conhecimento sobre a dinâmica deste processo. A análise em tempo real da concentração de EO no espaço-livre do esterilizador tem-se tornado prática comum e o desafio neste momento é prever o seu valor no interior da carga. Foi desenhado, concebido e desenvolvido um equipamento para determinar a difusividade e a solubilidade de EO, e a permeabilidade de diversos materiais ao gás, pela metodologia de tempo de atraso. A operação deste equipamento é baseada no princípio de medição de uma mudança transiente de pressão em condições de volume e temperatura constantes (abordagem pressão-variável) e permite a determinação do tempo de atraso e do fluxo de EO em estado estacionário através de diversos materiais. As experiências foram executadas com um material de campo cirúrgico, a uma temperatura típica de esterilização, i.e. 48 ˚C, e a uma pressão de 3,2x105 Pa. As propriedades de transferência do EO no campo cirúrgico foram usadas para modelizar a sua cinética numa carga industrial do mesmo material. A segunda lei de Fick demonstrou ser adequada na descrição do processo de transferência, o que foi validado pela utilização de dosímetros que integraram a concentração de EO durante o tempo de exposição. A etapa de arejamento é importante para reduzir os resíduos de EO a um nível seguro e neste contexto, prever a desorção do EO é uma importante ferramenta para a optimização global da esterilização por EO. A cinética de desorção de EO de diferentes materiais esterilizados foi avaliada numa gama de temperaturas de arejamento entre 1,5 e 59,0 °C. Os dados experimentais seguiram um processo de difusão Fickiano e as difusividades foram estimadas para dois materiais médicos têxteis e dois poliméricos. Os resultados apresentados nesta dissertação contribuem para uma melhor compreensão da dinâmica do processo de esterilização por EO e por conseguinte, para uma optimização e controlo eficiente deste processo.Ethylene oxide (EO) is a dominant sterilisation agent in medical device industry, due to its effectiveness and compatibility with most materials. Considering the exponential market growth of sensitive, complex and sophisticated medical devices, as well as custom procedure packs (that combine a large diversity of products and range of polymers) for use in specific medical and surgical procedures, EO emerges as the sterilisation method of choice. The process optimisation is a challenge, due to the fact that the global competition market requires cost effectiveness, flexibility and inherent reduction of turnaround time required to get the products to market, without compromising safety and compliance with regulatory requirements. Ethylene oxide sterilisation is a complex multi-parameter process that requires an aeration final step of the materials. The effectiveness of these processes is influenced by several variables (e.g. temperature, humidity, concentration of the agent, target material), so their optimisation requires knowledge of the influence of the conditions imposed and of their relations with the products. Mathematical modelling of the sterilisation and aeration processes allows the definition of optimal microbial inactivation and outgassing conditions, respectively. This allows cycle times and/or EO concentration reduction, as well as the comparison of different sterilisation processes. In this way it is possible to contribute to the development of processes with added efficiency and flexibility and, therefore, the parametric release of the sterilization arises scientifically supported. In this dissertation the influence of process conditions on EO sterilization of medical devices was studied. This is an implemented process in Bastos Viegas, S.A. company, since 2005. The main effects and interactions of temperature, ethylene oxide concentration and relative humidity on the inactivation of the Bacillus subtilis, var. niger (ATCC 9372), the reference microorganism used in the control of the process, were assessed. The experiments were carried out in sterilisation chambers, with a load of surgical drapes. A 23 full factorial experimental design was applied for evaluation of the effects of the three variables (under the common limits of operational conditions) on microbial lethality by EO sterilisation. The B. subtilis inactivation presented a sigmoidal behaviour and a Gompertz based model was successfully applied in experimental data fitting. Important characteristics of the curves, as initial shoulder and inactivation rate were considered model parameters. Temperature and ethylene oxide concentration were the variables that significantly affected those parameters, so additional experiments were carried out to include the effects of those process variables. A mathematical model for B. subtilis death prediction was developed, expressed in terms of temperature and EO concentration. Since the lethality was found to be directly related with the sterilant agent concentration, understanding EO sterilisation effectiveness requires attaining gas permeability of materials, as well as the knowledge of the process dynamics. The on-line analysis of EO concentration in the steriliser head-space is becoming common practice and the challenge now is to predict its value within the load. An apparatus was designed, conceived and developed for determination of EO diffusivity and solubility, and gas permeability of sheet materials, by lag time methodology. The operation of this apparatus is based upon the principle of measuring a transient change in pressure at conditions of constant volume and temperature (variable-pressure approach) and allows determination of lag time and steady state flow of EO through different materials. Experiments were carried out with a surgical drape material at a standard sterilisation temperature, i.e. 48 ˚C, and at a pressure of 3.22x105 Pa. The transport properties of EO through surgical drape were used for modelling its kinetics through an industrial load of the same material. The Fick‟s second law was adequate for describing the transport process, which was validated by the use of dosimeters that integrated EO concentration through exposure time. The aeration step is important for reducing EO residues to a safe level and in this context, prediction of EO desorption is a valuable tool for the overall optimisation of EO sterilisation. The kinetics of EO desorption, from different sterilised materials, was assessed within the range of aeration temperatures from 1.5 to 59.0 °C. The experimental data followed a Fickian diffusion process and diffusivities were estimated for two textile and two polymeric medical materials. The results presented in this dissertation contributes to a better understanding of the full dynamics of EO sterilisation and consequently, for an optimisation and efficient control of this process

    Juventud y arte de Silvano Lora. (Génesis y acción de un artista bajo la dictadura de Trujillo y parte de su primer exilio)

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    282 p.Tesis sobre la juventud y arte del artista dominicano Silvano Lora (1931-2003) en la que se analiza su expresión artística producto de las circunstancias políticas y sociales vividas. Desgrane de factores influyentes en su trayectoria como el arribo de la emigración europea, su integración en la Generación del 48 y sus primeras exposicionesnacionales e internacionales al amparo omnipresente de la dictadura. En lucha crítica contra Rafael L. Trujillo la oportunidad de exilio se presentará en un viaje iniciático que trastocará su vida

    A meta-programming framework for software evolution

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    Engineering self-awareness with knowledge management in dynamic systems: a case for volunteer computing

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    The complexity of the modem dynamic computing systems has motivated software engineering researchers to explore new sources of inspiration for equipping such systems with autonomic behaviours. Self-awareness has recently gained considerable attention as a prominent property for enriching the self-adaptation capabilities in systems operating in dynamic, heterogeneous and open environments. This thesis investigates the role of knowledge and its dynamic management in realising various levels of self-awareness for enabling self­adaptivity with different capabilities and strengths. The thesis develops a novel multi-level dynamic knowledge management approach for managing and representing the evolving knowledge. The approach is able to acquire 'richer' knowledge about the system's internal state and its environment in addition to managing the trade-offs arising from the adaptation conflicting goals. The thesis draws on a case from the volunteer computing, as an environment characterised by openness, heterogeneity, dynamism, and unpredictability to develop and evaluate the approach. This thesis takes an experimental approach to evaluate the effectiveness of the of the dynamic knowledge management approach. The results show the added value of the approach to the self-adaptivity of the system compared to classic self­adaptation capabilities

    An Approach for Guiding Developers to Performance and Scalability Solutions

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    This thesis proposes an approach that enables developers who are novices in software performance engineering to solve software performance and scalability problems without the assistance of a software performance expert. The contribution of this thesis is the explicit consideration of the implementation level to recommend solutions for software performance and scalability problems. This includes a set of description languages for data representation and human computer interaction and a workflow

    An Approach for Guiding Developers to Performance and Scalability Solutions

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    The quality of enterprise software applications plays a crucial role for the satisfaction of the users and the economic success of the enterprises. Software applications with unsatisfying performance and scalability are perceived by its users as low in quality, as less interesting and less attractive, and cause frustration when preventing the users from attaining their goals. This book proposes an approach for a recommendation system that enables developers who are novices in software perfor

    Review of Particle Physics

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    The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 2,143 new measurements from 709 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as supersymmetric particles, heavy bosons, axions, dark photons, etc. Particle properties and search limits are listed in Summary Tables. We give numerous tables, figures, formulae, and reviews of topics such as Higgs Boson Physics, Supersymmetry, Grand Unified Theories, Neutrino Mixing, Dark Energy, Dark Matter, Cosmology, Particle Detectors, Colliders, Probability and Statistics. Among the 120 reviews are many that are new or heavily revised, including a new review on Machine Learning, and one on Spectroscopy of Light Meson Resonances. The Review is divided into two volumes. Volume 1 includes the Summary Tables and 97 review articles. Volume 2 consists of the Particle Listings and contains also 23 reviews that address specific aspects of the data presented in the Listings. The complete Review (both volumes) is published online on the website of the Particle Data Group (pdg.lbl.gov) and in a journal. Volume 1 is available in print as the PDG Book. A Particle Physics Booklet with the Summary Tables and essential tables, figures, and equations from selected review articles is available in print, as a web version optimized for use on phones, and as an Android app.United States Department of Energy (DOE) DE-AC02-05CH11231government of Japan (Ministry of Education, Culture, Sports, Science and Technology)Istituto Nazionale di Fisica Nucleare (INFN)Physical Society of Japan (JPS)European Laboratory for Particle Physics (CERN)United States Department of Energy (DOE
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